In recent years, Wireless Local Area Network (WLAN) technologies have emerged as a fast-growing market. Among the various WLAN technologies, Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard is the dominating technology and is frequently used for WLANs.
Client devices within WLANs communicate with access points in order to obtain access to one or more network resources. An access point, referred to as an “AP,” is a digital device that operates as a gateway for a client device to establish a connection (e.g., a communicative coupling) with one or more networks (e.g., the Internet, an intranet, etc.). For example, an AP may be implemented as a wireless AP, which is configured to communicate wirelessly with one or more client devices as well as communicate with a networked device associated with the one or more networks, such as a controller for example, through a wired connection.
With respect to enterprise networks and other types of expansive multiple controller-based networks, conventional WLAN architectures do not manage the multicast stream subscriptions of client devices connected to the WLAN efficiently. For instance, a client device may communicatively couple to a first AP that is associated with a first controller located in a first Internet Protocol (IP) subnet and/or a first Virtual Local Area Network (VLAN). The client device may then subscribe to a multicast stream. Subsequently, the client device may roam to a second AP associated with a second controller due to a change in location of the client, device, failure of the first AP, greater signal strength for the second AP, or for a number of other reasons.
The second controller may be located in the first IP subnet or located in a second IP subnet. When the client device fails to unsubscribe to the multicast stream prior to roaming to the second AP and associating with the second controller, the multicast rooter may send unnecessary multicast transmissions. When the client device roams to a second controller that is located within a second IP subnet, the multicast router will continue to send the multicast stream to which the client device subscribed to the first IP subnet. When no other client devices are associated to a controller in the first IP subnet, the transmission of the multicast stream to the first IP subnet is unnecessary. The unnecessary transmission wastes network bandwidth between the multicast router and the one or more controllers located in the first IP subnet.
Currently, a multicast router will prune list of recipients of a multicast stream after the expiry of a particular amount of time. However, this amount of time may be in the order of minutes. Therefore, when a client device subscribing to a multicast stream roams without unsubscribing from the multicast stream and associates with a controller located in a second IP subnet, network bandwidth will be wasted until the multicast router prunes the list of recipients.